[Savestates] Rewrite Savestate-Indexer

[ScribbleTAS]

Splits the indexing portion of the SavestateHandlerServer into it's own file.

The implementation is the same as LoTAS-Light with a few improvements.

All advantages of this system are outlined in my proposal to LoTAS,
which aims to unify all different indexing systems into one.

Differences to LoTAS-Light

• /savestate with no savestates shows a help text on how to get started
• Added a warning when the tickrate was set to 0 during a savestate, so people know that you have to unpause the game with F8
• /folder savestates will try to open the current savestate folder for the world that the player is in: saves/savestates/<worldname>-Savestates/

API changes

• Added writeEnum() and readEnum() to the BufferBuilder to send enums via networking. Removed specialized methods in TASmodBufferBuilder as a result.
• Added a way to create and use certain GuiScreens during tickrate 0. If the Gui extends SubtickGuiScreen TASmod will support the keyTyped and mouseClicked methods in that gui, without recording them
• Added a way to retrieve TASmodKeybinds with KeybindManager.getKeybind(). Changed how keybinds are regiestered as a result.
• Added Component builder, a "backport" of the 1.20 library of the same name, to build ITextComponents. This made backporting all messages from LoTAS-Light a lot easier
• Properly added the SavestateStorageExtensionRegistry, which was more of a hack before this...

Upgrading

To use old savestates from the previous format, simply move all savestates in their own folder:

savestates/
├── Worldname-Savestate1
├── Worldname-Savestate2
├── Worldname-Savestate3
└── Worldname-info.txt

should be moved to

savestates/
└── Worlname-Savestates
    ├── Worldname-Savestate1
    ├── Worldname-Savestate2
    ├── Worldname-Savestate3
    └── Worldname-info.txt

Then ingame, load the Worldname-world (or type /savestate reload) and all savestates are converted to the new format

Caution

When doing this, you can't downgrade the savestates to the old format

TODO

• Readd trackerfile
• Add no savestate message
• Add tickrate 0 warning